Method of making an adapter assembly for electrical connectors



May 3, 1966 J. F. WILLIAMS, JR.. ETAL METHOD 0F MAKING AN ADAPTER ASSEMBLY FOR ELECTRICAL CONNECTORS Filed Dec. 16, 1965 R. s mmm/MM Tmnm Nm. EMA A Wwe. .l C Emd. r m9- .mb eC m m n s4 W Wg w Lui. d c Y @uw .U BMA 2 lo 5./ C Aol La pf United States Patent O 3,248,778 METHOD OF MAKING AN ADAPTER ASSEMBLY FOR ELECTRICAL CONNECTORS Joseph F. Williams, Jr., and Clarence A. Boyce, Indianapolis, Ind., assignors to The Buehler Corporation, Indianapolis, Ind., a corporation of Indiana Filed Dec. 16, 1963, Ser. No. 331,037 2 Claims. (Cl. 29-155.5)

This invention relates lvgenerally to electrical cable 'assem-blies, and more particularly to electrical connectors j phenol plugs and sockets.

In many instances, particularly Where such connectors are to be employed in aircraft, there is a requirement that they be made of a light metal such as aluminum, for example. Another typical requirement is that a braided shield be secured to the connector to house the electrical conductors attached to the connector.

The braided shielding is frequently made of ya large number of strands of tinned copper wire braided together. Obviously, because the shielding is braided, it does not entirely enclose the flexible conduit extending inside of it. The usual practice is to provide approximately 50% coverage. It will 'be recognized, however, that tinned copper braid is not easily secured to an aluminum connector. Moreover, a 92% coverage by the braid is now being required by some users. This has made it extremely diflicult to secure the braid to the connectors. Heretofore, the most feasible known method has been to use an electrically conductive epoxy material to seal the braid tothe connector. The electrical conductivity is essential to be certain that the shielding is electrically connected to the aluminum connector at all times.

There are several important disadvantages to the present method of attaching the braid to the connector. To obtain the proper conductivity of the epoxy, silver has been incorporated therein and the cost of the material is approximately $50.00 for a half pint. Moreover, when the epoxy material is prepared for use, it remains sufciently fluid for use for a period, of only ten minutes. It also requires curing for several hours at elevated temperature. Moreover, there is the possibility of thermal expansion and contraction of the joint in use causing a failure of the joint mechanically or electrically or both.

Other means have been considered `for securing the.

braid to the connector but heretofore, t-hey have had substantial disadvantages and have not been used to any considerable extent.

It is, therefore, a general object of the present invention to provide an improved electrical connecting device.

A further object is to provide an effective means and method of securing braided shielding to an electrical connector.

A further object is to provide effective means and method of securing together a braid of one material and a connector of another material to provide a sound rnechanical and electrical connection therebetween.

A still further object is to provide an electrical connector `and braid assembly which is easily manufactured even though the braid is a very tight braid having a high percentage of coverage.

Described briefly, the device of the present invention ICC has an annular surface of copper, or nickel, cadmium or other conductive material deposited as by electroplating or other means onto a portion of the aluminum connector. The surface is tinned and a tinned braid is then positioned on the surface. A heated clamp is then placed on the braid clamping it to the surface tand -applying heat at the same time which thereupon solders the braid to the connector.

The full nature of the invention will be understood from the accompanying drawings and the following description and claims.

FIG. lis an elevational view of the adapter portion of a typicalV connector, having the shielding secured thereto according to the present invention.

FIG. 2 is an enlarged section taken along the line 2-2 in FIG. l and viewed in the direction of the arrows.

Referring to the drawings in detail, the adapter lll, having the axis l2, has a shoulder flange 13 and threads 14 thereon by which it may Ibe assembled into .a complete conne-ctor assembly which can include pins or sockets attached to the insulated conductors 16, `17, 18, and 19, for example. However, these additional details of the connector assembly are not important .to the present invention and therefore they are not shown in the drawings. Flexible shielding l21 is secured to the adapter. A typical ex ample of this shielding is a braid of ninety-six strands of #36 tinned copper wire.

As shown in FIG. 2, a plurality of conductors passes axially through the adapter. Each of the conductors is insulated as at 22, for example, `and has ya protective plastic tube 23 surrounding it. Though only four conductors are shown, common practice is to run many conductors through such an adapter, and the present invention in no way limits the number which can be employed.

An integral annular shoulder 24 is provided on the outer cylindrical surface 26 of the adapter. Threads 27 may be incorporated between the shoulder 24 and the ange 13 for manufacturing purposes, if desired, but are not essential to the present invention.

As suggested previously, the typical practice is to attach the braid to the shoulder 24 by the use of au epoxy adhesive material. However, according to the present invention, a .layer 28 of copper or other conductive material is deposited onto the shoulder 24 of the adaptor prior to insertion of the wires and prior to the attachment of any of the parts shown in the drawing. The electroplating can be done in the manner well known t-o those skilled in the art. However, it is necessary to have the cylindrical surface of the shoulder quite clean before the plating begins. In order to clean this surface, a process can be employed as disclosed in the Metal Finishing Guide Book, 1961 edition, page 254, paragraph 5. This book was published by the Metals and Plastics Publications, Inc., 381 Broadway, Westwood, New Jersey.

The next step according to the present invention is to tin the exterior of the copper coating 28 and this can be accomplished readily by dipping in a solder pot using 60-40 or 50-50 lead-tin or other appropriate materials which are well known.

Then the conductors may be assembled with the adapter, and a suitable plastic sealing tube 29 is secured around to the surface 26. The sealing tube 29 may be shrunk onto the surface 26 in a manner well known in the production of shielded connector cables. Then the tinned copper braid is wound on by conventional means.

After Winding the braid in place, heated tongs or clamps are pressed radially against the portion 31 of the shielding encircling the shoulder 24. Heat is applied to the tongs or clamps and soldering of the shielding to the tinned copper takes place. The portion 32 of the shielding can be crimped onto the threads 27, if desired, but this is not necessary.

The present invention provides a mechanically and electrically sound connection of the braid to the connector and is unaffected by any. environmental temperatures likely to be encountered thereafter. This is in contrast to conventional assemblies Where epoxies have been used and the resistance increases at 180 Fahrenheit for some reason which is not clearly understood. The present invention avoids such phenomenon. The present invention requires no curing time and the assembly is completed when the heated clamps are removed.

While the invention has been disclosed and described in some detail in the drawings and foregoing description, they are to be considered as illustrative and not restrictive in character, as other modifications may readily suggest themselves to persons skilled in 'this art and Within the broad scope of the invention, reference being had to the appended claims.

The invention claimed is:

1. A method of attaching a copper braided sleeve to an aluminum plug-and-socket adapter member, said method comprising the steps of: electroplating a layer of copper onto a solid convex clean aluminum surface of the adapter member to provide a copperplate surface thereon; dipping the copperplate surface into molten leadtin solder and thereby tinning the said copperplate surface; clamping a solder tinned inner surface of a braided copper sleeve onto the tinned copperplate surface; applying heat from clamping means through the braided sleeve to the tinned copperplate surface and thereby raising the temperature of said braided sleeve and said copperplate surface at the area of contact of their respective tinned 35 surfaces sufficiently for fusion of the tinning solder thereon; allowing the fused tinning solder to solidify While the said braided sleeve remains clamped onto said copperplate surface; and removing said clamping means after the said fused solder has solidified.

2. A method of attaching a copper braided sleeve to an aluminum adapter for a plug-and-socket connector 5 assembly, said method comprising the steps of: electroplating a circular layer of copper onto a solid convex circular clean aluminum surface of the adapter to provide a copperplate ring surface thereon; dipping the copperplate ring surface into molten lead-tin solder and thereby tinning the said copperplate ring surface; clamping a solder tinned inner surface of a iiexible braided copper sleeve onto the tinned copperplate ring surface; applying heat to the tinned copperplate ring surface from clamping means through the braided sleeve and thereby raising the temperature of said braided sleeve and said copperplate surface at the area of contact of their respective tinned surfaces sufficiently for fusion of the tinning solder thereon; allowing the fused tinning solder to solidify While the said braided sleeve remains clamped onto said copperplate surface; and removing said clamping means after the said fused solder has solidified.

References Cited by the Examiner UNITED STATES PATENTS 2,118,672 5/1938 Green 174-36 2,438,146 3/1948 Candee et al. 174-68 2,513,365 7/1950 Rogoif 29-492 2,557,130 6/1951 McGee et al 339-102 2,636,072 4/1953 Lamoureaux 174-5055 2,691,058 10/1954 Millar 174-36 2,972,657 2/1961 Stemke 174-94 XR 3,067,489 12/1962 Hoffman 29-155.55 3,074,150 1/1963 Berg 29-155.55

WHITMORE A. WILTZ, Primary Examiner.

LARAMIE E. ASKIN, R. W. CHURCH, DAKAP,

Examiners. 

1. A METHOD OF ATTACHING A COPPER BRAIDED SLEEVE TO AN ALUMINUM PLUG-AND-SOCKET ADAPTER MEMBER, SAID METHOD COMPRISING THE STEPS OF: ELECTROPLATING A LAYER OF COPPER ONTO A SOLID CONVEX CLEAN ALUMINUM SURFACE OF THE ADAPTER MEMBER TO PROVIDE A COPPERPLATE SURFACE THEREON; DIPPING THE COPPERPLATE SURFACE INTO MOLTEN LEADTIN SOLDER AND THEREBY TINNING THE SAID COPPERPLATE SURFACE; CLAMPING A SOLDER TINNED INNER SURFACE OF A BRAIDED COPPER SLEEVE ONTO THE TINNED COPPERPLATE SURFACE; APPLYING HEAT FROM CLAMPING MEANS THROUGH THE BRAIDED SLEEVE TO THE TINNED COPPERPLATE SURFACE AND THEREBY RAISING THE TEMPERATURE OF SAID BRAIDED SLEEVE AND SAID COPPERPLATE SURFACE AT THE AREA OF CONTACT OF THEIR RESPECTIVE TINNED SURFACES SUFFICIENTLY FOR FUSION OF THE TINNING SOLDER THEREON; ALLOWING THE FUSED TINNING SOLDER TO SOLIDIFY WHILE THE SAID BRAIDED SLEEVE REMAINS CLAMPED ONTO SAID COPPERPLATE SURFACE; AND REMOVING SAID CLAMPING MEANS AFTER THE SAID FUSED SOLDER HAS SOLIDIFIED. 